21531432310 has 32 divisors (see below), whose sum is σ = 39359421504. Its totient is φ = 8478960000.

The previous prime is 21531432289. The next prime is 21531432319. The reversal of 21531432310 is 1323413512.

It is a happy number.

It is a super-2 number, since 2×21531432310² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21531432319) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 476080 + ... + 519340.

It is an arithmetic number, because the mean of its divisors is an integer number (1229981922).

Almost surely, 2^21531432310 is an apocalyptic number.

21531432310 is a deficient number, since it is larger than the sum of its proper divisors (17827989194).

21531432310 is a wasteful number, since it uses less digits than its factorization.

21531432310 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44040.

The product of its (nonzero) digits is 2160, while the sum is 25.

Adding to 21531432310 its reverse (1323413512), we get a palindrome (22854845822).

The spelling of 21531432310 in words is "twenty-one billion, five hundred thirty-one million, four hundred thirty-two thousand, three hundred ten".